Advanced sleep phase syndrome (ASPS) and delayed sleep phase syndrome (DSPS) are conditions that cause your sleep schedule to be out of line with what is considered “normal” by society’s standards. ASPS and DSPS don’t necessarily affect 

If you have an unusual sleep schedule due to working a job or going to school outside of typical daytime hours, it doesn’t necessarily mean you have ASPS or DSPS. When people do have these conditions, they often want to follow a different sleep schedule, but their bodies don’t seem to let them.

If you feel like you may have signs of ASPS or DSPS, talk to your doctor. Treatment can help you safely and effectively adjust your sleeping patterns or cope with keeping an unusual schedule.

ASPS, also called advanced sleep-wake phase disorder, causes you to be an extreme early bird. If you have this condition, for example, you may find yourself becoming very sleepy in the late afternoon and needing to get to bed in the early evening, despite wanting to stay awake longer. You may then find yourself naturally waking up extremely early in the morning, lying awake until your alarm eventually goes off. [1]

Get tired and fall asleep earlier in the day than you want to

Wake up early in the morning and can’t get back to sleep

Experience these symptoms nearly every day, including days when you have work or school as well as your free days

Have had these symptoms for at least three months

ASPS typically occurs due to predispositions or development changes in your circadian rhythm (internal body clock) and sleep drive (the process in your body that makes you feel increasingly sleepy the longer you are awake).1 These changes may develop because of genetics — about 

 of people with ASPS have a family member with the condition. Additionally, ASPS is more common among older adults.2

On the other end of the spectrum, DSPS turns you into a night owl. If you have DSPS, you may find yourself regularly staying awake until the early hours of the next morning. In the absence of any responsibilities the next day, you might find yourself sleeping in until noon or later. Some experts also refer to DSPS as delayed sleep-wake phase disorder. [1]

You may want to talk to your doctor about DSPS if you: [1]

Don’t start feeling sleepy or aren’t able to fall asleep until very late

Struggle to wake up in the morning at a certain time

Experience these late sleep-wake times regardless of whether or not you are trying to follow a certain schedule

Have had these symptoms for three months or more

Like ASPS, DSPS can develop due to the underlying biology of  your circadian rhythm and sleep drive.1 DSPS is also more common in young adults and teens; about 

 of people within these age ranges have the condition. Additionally, many people with mental health disorders also have DSPS.3

Attention-deficit hyperactivity disorder (ADHD)

 is strongly linked to DSPS in some studies. ADHD is a condition that causes you to be inattentive (have trouble focusing or staying organized), hyperactive (moving around a lot when it is not appropriate), and/or impulsive (acting or speaking quickly without thinking it through). [4]

 people with ADHD may have DSPS.5 Studies have found changes in the genes that control circadian rhythms in people with ADHD. This causes certain body processes, such as hormone production, to occur 1.5 hours later than they would in people without ADHD. [5], [6]

DSPS is also more common in people with psychiatric conditions like bipolar disorder, obsessive-compulsive disorder, depression, and substance use disorder.1

Changing your sleeping patterns can be difficult on your own, but certain strategies can help. Although ASPS and DSPS look a little different, their recommended treatments are very similar.

 can be a good place to start. Sleep hygiene consists of habits that can help you develop higher-quality, more consistent sleep. You will want to try:7

Staying away from coffee in the afternoon and evening

Avoiding naps, especially later in the day

Staying out of your bedroom except when you want to sleep

Removing distractions involving bright lights or noise from your bedroom

Getting out of bed and doing something else for a bit if you can’t fall asleep

You can also try adjusting your lifestyle to match your natural sleep rhythm rather than fighting it. For example, if you have ASPS, you could try working or taking classes a little earlier in the day or meeting up with friends for happy hour rather than for a late dinner. If you have DSPS, you could try switching to an evening or night shift or making plans with loved ones later in the evening.

 or phototherapy is also an effective technique for treating ASPS and DSPS. This method involves using bright lights to shift your sleep-wake times and reset your circadian rhythms. If you have ASPS, this may involve surrounding yourself with light in the late afternoon or evening hours, while DSPS is treated with light exposure in the morning.1

Although Cognitive Behavioral Therapy for Insomnia (CBT-I) was originally developed as an insomnia treatment, it is also an effective and well-known therapy for both ASPS and DSPS. CBT-I helps you learn more about your personal sleep habits and change your thoughts, attitudes, and behaviors surrounding rest.1

People with ASPS and DSPS often struggle with the pressure surrounding what society considers to be “normal” sleep and awake hours. CBT-I helps treat both of these syndromes because it targets how we feel about our sleeping patterns. To learn more about CBT-I, read Dawn’s 

If you are struggling to improve your sleep, try 

. We provide tailored CBT-I advice about sleep habits thanks to in-depth work with a one-on-one sleep coach. To learn more, fill out our 

Culnan, E., McCullough, L. M., & Wyatt, J. K. (2019). Circadian Rhythm Sleep-Wake Phase Disorders. 

(3), 527–543. https://doi.org/10.1016/j.ncl.2019.04.003

https://stanfordhealthcare.org/medical-conditions/sleep/advanced-sleep-phase-syndrome.html

https://stanfordhealthcare.org/medical-conditions/sleep/delayed-sleep-phase-syndrome.html

National Institute of Mental Health. (2021, September). 

Attention-Deficit/Hyperactivity Disorder. 

https://www.nimh.nih.gov/health/topics/attention-deficit-hyperactivity-disorder-adhd

Lunsford-Avery, J. R., & Kollins, S. H. (2018). Editorial Perspective: Delayed circadian rhythm phase: a cause of late-onset attention-deficit/hyperactivity disorder among adolescents?. 

Journal of child psychology and psychiatry, and allied disciplines, 59

(12), 1248–1251. https://doi.org/10.1111/jcpp.12956

Wajszilber, D., Santiseban, J. A., & Gruber, R. (2018). Sleep disorders in patients with ADHD: impact and management challenges. 

, 453–480. https://doi.org/10.2147/NSS.S163074

https://medlineplus.gov/healthysleep.html

Learn about advanced sleep phase syndrome (ASPS) and delayed sleep phase syndrome (DSPS).

Advanced Sleep Phase Syndrome vs. Delayed Sleep Phase Syndrome | Dawn Health

Advanced Sleep Phase Syndrome vs. Delayed Sleep Phase Syndrome

As technology becomes more advanced, and tools like smartphones and fitness watches become better at collecting health data, more people than ever before have started tracking their sleep. In 2017, about 

 said they used sleep trackers regularly or occasionally to improve their rest. [1]

Sleep trackers may help you become more aware of your sleeping patterns and take note of any potential problems. However, many studies have found that they tend not to be very accurate in their measurements. There is also a risk that using these devices may actually lead to an unhealthy preoccupation with sleep that can contribute to 

There are many types of devices that can track your sleep. They come with varying degrees of complexity — some sleep trackers may record a couple of different types of information, while others may paint a very detailed picture of how you slept at each point during the night. [2]

Some sleep trackers are wearable. They consist of devices that you put on your wrist, finger, or head. Wearable trackers stay in contact with your skin as they continually collect data. Many of these devices also gather information about your physical activity levels and calories consumed or burned.

Other sleep trackers are non-wearable devices. For example, you may collect sleep data with a sleep tracker app on your smartphone. In this case, you may place your phone on the bed next to you as you sleep. You can also use sleep monitors that sit on or under your mattress. Some of these devices may also report information about the conditions of your room, including temperature or humidity.

What Type of Information Do Sleep Trackers Collect?

Sleep trackers typically measure whether you’re asleep or not using metrics like your movements, heart rate, body temperature, and breathing patterns. All of these body processes undergo changes as you move through the different stages of sleep.

. During the first three stages, sleep starts out light and gets progressively deeper — it is deepest during stage 3 sleep. Your heart rate and body temperature decrease with each stage. The fourth sleep stage is rapid eye movement (REM) sleep, in which your heart rate increases, your breathing becomes more irregular, and you dream. [3]

Sleep trackers may use information like your heart rate to report that you were in a period of “light sleep” or “heavy sleep,” but this isn’t exactly the same as reporting your sleep stage. Studies have found that sleep trackers often can’t accurately detect which stage a person is in. [4]

The best way to measure your sleep stages is through tests like 

 that measure brain waves. You can’t go through these tests at home with sleep trackers; you undergo them in sleep clinics. Polysomnography and other tests administered by sleep specialists can help officially diagnose sleep disorders. [4]

Sleep trackers aren’t perfect. Unfortunately, many companies don’t share exactly how their tracking programs work, which means it can be hard to determine their accuracy. Additionally, the vast majority of sleep trackers are categorized as “lifestyle/entertainment” devices. They aren’t regulated by the Food and Drug Administration (FDA), which means that no one is checking to make sure the devices are accurate or based on current scientific information.5

Multiple studies have found that sleep trackers aren’t as accurate as we might hope. Sleep trackers: [4], [6]

Are likely to report that you got more sleep than you really did

Are very inaccurate when it comes to measuring how long it takes for a person to fall asleep

Often incorrectly report that you’re sleeping when you’re actually awake, especially if you have chronic health conditions

Are poor at distinguishing how deep a person’s sleep is

Despite their limitations, sleep trackers may be helpful for some people. One benefit is that they can make you more aware of your sleep and encourage you to learn more about how to get better rest. [5]

Another positive is that they can give you a broad overview of your overall sleeping patterns. If you’re trying to 

, such as going to bed and waking up at the same time each day, a sleep tracker can help you determine whether you’re on track. It may also point out other helpful insights — for example, you may notice that you get more sleep on days when you’ve been more physically active. [4]

A sleep tracker could also help you detect any overarching problems, such as being woken up early at the same time each day. It may also help you identify potential signs of sleep disorders. For example, loud snoring or waking up multiple times throughout the night could point to sleep apnea.

In the long term, sleep tracker data could also be combined with data from other health devices to help you and your doctor better understand your health.5

One problem with sleep trackers is their potential inaccuracy. People relying on these devices may think they’re getting more or less sleep than they really are. Additionally, the devices often can’t reliably tell what sleep stage you’re in, which means it’s hard to measure your sleep quality. [4]

Additionally, some people using trackers become so preoccupied with their sleep stats that they actually start getting worse sleep. Experts call this “

.” For example, you may find that if your sleep tracker is regularly telling you that you’re not hitting your targets, you develop increased anxiety surrounding sleep. You may even be tempted to spend extra time in bed, which can worsen insomnia. [4]

Although sleep tracker devices and apps may provide you with a lot of data, they don’t always help you understand how to best use this information. For example, you may see that you’re not getting a lot of deep sleep, but feel unsure about how to change this — your sleep stages are largely outside of your control.

Instead, you may want to focus on what you can control, such as what time you lay down in bed and how long you spend trying to sleep. Sleep tracker devices may help, but aren’t strictly necessary when it comes to making these sorts of changes.

Sleep trackers can help define sleeping patterns and are a fantastic starting point to improve overall sleep. However, they may 

 when paired with other strategies such as Cognitive Behavioral Therapy for Insomnia (CBT-I).4 During 

, you work with a therapist or online program to adjust your behaviors and beliefs surrounding sleep. CBT-I is known to be very effective in treating insomnia. [7]

CBT-I can provide tailored one-on-one coaching that can teach you how to make the most of your sleep. For the most effective results, use your sleep tracker to start a conversation with your therapist.

To take the first step toward getting a better night’s sleep, 

 to get matched with a sleep coach who can provide personalized advice.

Percentage of U.S. adults that use apps to track their sleep as of 2017, by gender.

https://www.statista.com/statistics/699434/us-adults-that-use-apps-to-track-sleep-by-gender/

de Zambotti, M., Cellini, N., Goldstone, A., Colrain, I. M., & Baker, F. C. (2019). Wearable Sleep Technology in Clinical and Research Settings. 

Medicine and science in sports and exercise, 51

(7), 1538–1557. https://doi.org/10.1249/MSS.0000000000001947

Patel, A.K., Reddy, V., & Araujo, J.F. (2021, April 22). Physiology, Sleep Stages. 

https://www.ncbi.nlm.nih.gov/books/NBK526132/

Baron, K. G., Abbott, S., Jao, N., Manalo, N., & Mullen, R. (2017). Orthosomnia: Are Some Patients Taking the Quantified Self Too Far?. 

Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, 13

(2), 351–354. https://doi.org/10.5664/jcsm.6472

Khosla, S., Deak, M. C., Gault, D., Goldstein, C. A., Hwang, D., Kwon, Y., O'Hearn, D., Schutte-Rodin, S., Yurcheshen, M., Rosen, I. M., Kirsch, D. B., Chervin, R. D., Carden, K. A., Ramar, K., Aurora, R. N., Kristo, D. A., Malhotra, R. K., Martin, J. L., Olson, E. J., Rosen, C. L., … American Academy of Sleep Medicine Board of Directors (2018). Consumer Sleep Technology: An American Academy of Sleep Medicine Position Statement. 

Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, 14

(5), 877–880. https://doi.org/10.5664/jcsm.7128

Conley, S., Knies, A., Batten, J., Ash, G., Miner, B., Hwang, Y., Jeon, S., & Redeker, N. S. (2019). Agreement between actigraphic and polysomnographic measures of sleep in adults with and without chronic conditions: A systematic review and meta-analysis. 

, 151–160. https://doi.org/10.1016/j.smrv.2019.05.001

Agency for Healthcare Research and Quality. (2017, August 1). 

https://effectivehealthcare.ahrq.gov/products/insomnia/consumer

Sleep trackers are now common. Learn how accurate they are and if they really can show you how you slept.

How Accurate are Sleep Trackers? |  Dawn Health

How Accurate are Sleep Trackers?

If you have problems falling asleep, staying asleep, or waking up too early, you may have insomnia — a common sleep disorder. Insomnia may make you feel like you barely sleep at night and it may cause you to feel really tired during the day. While occasional sleeplessness is common, you may have chronic insomnia if your sleep troubles have been ongoing for at least a month. [1]

There are several options for insomnia treatment. If your sleeping problems are caused by an underlying medical disorder, addressing that condition is always a good first step. Additionally, certain medications and lifestyle changes can help you get a better night’s sleep. The most well-known and effective option is 

cognitive behavioral therapy for insomnia (CBT-I)

, [2] CBT-I is a personalized program that addresses your relationship with sleep and how best to support and promote healthy sleep patterns.

Several types of medications may help you sleep better. Some sleeping aids can be bought over-the-counter. Some of the most popular options include: [3]

Diphenhydramine, which goes by brand names like Aleve PM, Benadryl, and ZzzQuil

Other medications are sedatives that are prescribed by a doctor. Prescription sleeping aids include: [4]

When going through a severe episode of insomnia, it is typical to reach for these types of aids. Medications for insomnia may help you get a full night’s sleep when nothing else will, and higher-quality sleep can help protect your health. [3]

Unfortunately, sleep medications can also have drawbacks. It is a good idea to talk to your doctor to find out whether these drugs may be helpful for your personal needs.

Experts recommend using sleeping aids only as a temporary fix. They are not a good long-term solution, for several reasons:

The hangover effect — These drugs make some people feel “hungover.” You may feel extra groggy the day after using sleep aids. [3]

You can build up tolerance to over-the-counter drugs — These medications typically work well at first. However, your body quickly gets used to them, making these aids increasingly less effective the longer you use them. [3]

You may become addicted to prescription drugs — If you use sleep aids too often, you may develop a dependence on them and be unable to fall asleep without them. [2]

Side effects — Different types of sleeping pills can lead to different health issues, including headaches, dizziness, tiredness, nausea, diarrhea, and memory and thinking problems. [4]

It is also quite popular to treat insomnia with antidepressants. These medications may alter levels of certain brain chemicals that affect sleep. However, symptom relief can take several months to achieve and is not also sustainable if you stop taking antidepressants. Also, paradoxically, some antidepressants can negatively impact sleep quality. To learn more about using antidepressants to manage insomnia, 

CBT-I is a program that can help you develop better habits and attitudes surrounding sleep. It can be understood as a therapy that creates a bond between your behavior, your thoughts, and your emotions to reprogram your sleep patterns. CBT-I can provide a long-term solution to sleeping problems.5 To learn more about cognitive behavioral therapy for sleep and check out an in-depth explanation of the “CBT-I triangle,” read our 

CBT-I also gives you the tools you need to change unhelpful thought and behavioral patterns.6 Purposely working to build up beneficial attitudes and behaviors through CBT-I can help you develop more positive emotions toward sleeping and feel more motivated to stick to new sleep habits.

CBT-I is the gold standard treatment for insomnia, recommended by both the American Academy of Sleep Medicine and the American College of Physicians. [7] There are a few reasons why experts recommend CBT-I over medication: [5], [7]

CBT-I tackles the underlying factors that initially lead to insomnia. Sleep aids, on the other hand, merely address surface-level insomnia symptoms.

Because CBT-I more directly taps into the causes of insomnia, it provides longer-lasting relief for sleep problems.

Medications aren’t always effective at treating insomnia. CBT-I has a high success rate and is especially helpful for people who have mental health issues that may be contributing to insomnia, such as anxiety.

You don’t have to worry about tolerance, dependence, or addiction when using CBT-I.

CBT-I doesn’t lead to any uncomfortable or harmful side effects.

CBT-I is one of the best treatments for insomnia. It may work better and be better for your health as compared with sleeping pills. If you want to learn more about CBT-I and gain tools for better sleep, check out 

. Here, you can learn more about how it’s possible to relieve sleeplessness with the right treatment and effort.

If you’re interested in trying cognitive behavioral therapy for sleep, fill out our 

 to see if it may be a good fit for you.



MedlinePlus Medical Encyclopedia. (2022, April 1). 

https://medlineplus.gov/ency/article/000805.htm

Sleep Aids: Understand Over-the-Counter Options

https://www.mayoclinic.org/healthy-lifestyle/adult-health/in-depth/sleep-aids/art-20047860

Prescription Sleeping Pills: What’s Right for You?

https://www.mayoclinic.org/diseases-conditions/insomnia/in-depth/sleeping-pills/art-20043959

Insomnia Treatment: Cognitive Behavioral Therapy Instead of Sleeping Pills. 

https://www.mayoclinic.org/diseases-conditions/insomnia/in-depth/insomnia-treatment/art-20046677

InformedHealth.org. (2016, September 8). 

https://www.ncbi.nlm.nih.gov/books/NBK279297/

Feuerstein, S., Hodges, S. E., Keenaghan, B., Bessette, A., Forselius, E., & Morgan, P. T. (2017). Computerized Cognitive Behavioral Therapy for Insomnia in a Community Health Setting. 

(2), 267–274. https://doi.org/10.5664/jcsm.6460

Learn about cognitive behavioral therapy for insomnia and how this can be used as an alternative to sleep medication.

Using CBT-I Instead of Medication | CBT-I as an Alternative to Sleep Medication | Dawn Health

Using CBT-I Instead of Medication

Getting enough sleep is important for physical and mental health. It can boost your immune system, protect against chronic health conditions such as heart disease, and help you think more clearly. [1]

For better sleep, you will want to consider creating a consistent sleep schedule — a pattern of waking up at the same time each day. When your sleep schedule changes from day to day, you are more likely to have poorer quality sleep. [2] Improving an erratic sleep schedule to make it more regular can help you sleep longer each night and feel less tired during the day. [3], [4]

Starting a Routine is the Way to Change Your Sleep Schedule

Nearly half of the actions we take every day are a result of habit. [5] If you’re trying to get better sleep, building a routine that you naturally follow each morning and evening will be easier than trying to motivate yourself to make beneficial decisions on a daily basis. Additionally, once your body has followed your new schedule for long enough, there will be physical cues that deepen this schedule, leading to more reliable and more restorative rest.

There are several steps you can take to get your sleep schedule back on track. Practice these each day to feel better rested.

It's hard to go from full work mode into sleep mode. Pick a time each night to start winding down for sleep. Try to keep the same time for both weekdays and weekends.

Unwinding is crucial for a good night’s sleep. Put your phone on airplane mode 1-2 hours before getting into bed to make sure your brain has switched off from work and has entered relaxation mode.

Before bedtime, start calming your brain and body with an activity like reading, listening to your favorite music, meditation, or taking a warm bath. Make sure the activity is something you like — getting ready for bed shouldn’t be yet another chore! Pick an activity you’ll look forward to and is also soothing.

Scientific studies tell us that habits are formed through “chunking” — that is, we tend to perform routines in which multiple actions are habitually performed together, in the same order. [7]

You likely go through several behaviors while getting ready for bed, such as putting on pajamas, brushing your teeth, and washing your face. Write down each of these steps and perform them in the same order each night, starting at the same time. This will help you build a routine that signals to your brain that it’s time for sleep.

It is tempting to sleep in when we don’t have to get up, especially if we have been struggling with sleep. Try getting up within the same 15 minute window of time every single day, no matter what time you went to bed or how well you slept.

Your circadian rhythm (internal body clock) is synchronized with natural sunlight and electric lights are often ineffective in supporting these rhythms.8 Try stepping outside for a bit when you first wake up, or eating breakfast next to a window, in order to better signal sleeping and waking hours to your body. If you must use artificial lighting, invest in a bulb or lamp that mimics daylight.

When building your sleep schedule, plan to get at least seven hours of sleep per night — the amount recommended by the National Sleep Foundation.9 For someone working a typical “9-to-5” schedule, this may look like going to bed by 10:00 to 11:00 p.m. and waking up by 6:00 a.m. This means you would start your wind-down routine between 8:00 and 9:00pm.

Starting a routine that works well may be trickier if you have a more irregular schedule for work or school. However, it’s still possible to get enough sleep! For example, a 12-hour night shift sleep schedule for someone working from 7:00 p.m. to 7:00 a.m. might include going to bed at 8:00 or 9:00 a.m. and sleeping until 4:00 p.m.

Staying motivated with your newly-created bedtime routine isn’t always easy at first, but will become less difficult over time. To help yourself stick to your new habits, you may want to turn to a psychological tool — cognitive behavioral therapy (CBT).

CBT is effective at helping people live better lives. The foundation of CBT can be thought of as a triangle, with three different key factors: [10]

Thoughts — The things you believe about yourself, your circumstances, and the people around you

Behaviors — The things you do and the way you act

Feelings — The emotions you have surrounding a particular situation

The CBT model has lots of research about how these three factors are all connected. Your thought patterns and the way you behave on a daily basis help shape each other, and also influence the way you feel. Your feelings, in turn, influence your beliefs and actions. [10]

cognitive behavioral therapy for insomnia

 or CBT-I can help people with sleeping problems. Scientific studies have shown that this type of treatment is very effective. It addresses the underlying causes of insomnia instead of just relieving symptoms.

CBT-I uses the CBT triangle to connect your thoughts, behavior, and feelings. It helps reprogram your subconscious and create new habits that are more in line with your goals.

When using CBT-I to build a better sleep schedule, you may work to change certain thought patterns, such as: [10], [11]

Learning more about how sleep works, so that you can get rid of incorrect beliefs

Using problem-solving skills to attack the specific issues that are keeping you awake

Addressing negative thoughts that keep you up at night

This program will also challenge you to change certain behaviors in your sleep schedule. For example, you may need to avoid napping, change your bedroom environment, and only spend time in your bedroom while sleeping. [11], [12]

Is CBT-I a good fit for your own needs? Learn more by filling out our 

Hoping for a better night’s rest? You’re already on the right track by looking for information that can help improve your sleep. To hear more about another person’s struggles with insomnia — and their eventual recovery — read 

An Anxious Sleeper’s Guide to Better Sleep

Building a consistent sleep schedule is possible if you work to align your thoughts and feelings with your behaviors. If you’re interested in learning more about CBT-I, check out Dawn’s many resources, articles, and tools geared towards curing sleep problems.

National Institutes of Health. (2013, April).

 The Benefits of Slumber: Why You Need a Good Night’s Sleep

https://newsinhealth.nih.gov/2013/04/benefits-slumber

Irish, L. A., Kline, C. E., Gunn, H. E., Buysse, D. J., & Hall, M. H. (2015). The role of sleep hygiene in promoting public health: A review of empirical evidence. 

, 23–36. https://doi.org/10.1016/j.smrv.2014.10.001

Paterson, J. L., Reynolds, A. C., & Dawson, D. (2018). Sleep Schedule Regularity Is Associated with Sleep Duration in Older Australian Adults: Implications for Improving the Sleep Health and Wellbeing of Our Aging Population. 

(2), 113–122. https://doi.org/10.1080/07317115.2017.1358790

Manber, R., Bootzin, R. R., Acebo, C., & Carskadon, M. A. (1996). The effects of regularizing sleep-wake schedules on daytime sleepiness. 

(5), 432–441. https://doi.org/10.1093/sleep/19.5.432

Mendelsohn A. I. (2019). Creatures of Habit: The Neuroscience of Habit and Purposeful Behavior. 

(11), e49–e51. https://doi.org/10.1016/j.biopsych.2019.03.978

Smith, K. S., & Graybiel, A. M. (2016). Habit formation. 

(1), 33–43. https://doi.org/10.31887/DCNS.2016.18.1/ksmith

Wright, K. P., Jr, McHill, A. W., Birks, B. R., Griffin, B. R., Rusterholz, T., & Chinoy, E. D. (2013). Entrainment of the human circadian clock to the natural light-dark cycle. 

(16), 1554–1558. https://doi.org/10.1016/j.cub.2013.06.039

Hirshkowitz, M., Whiton, K., Albert, S. M., Alessi, C., Bruni, O., DonCarlos, L., Hazen, N., Herman, J., Katz, E. S., Kheirandish-Gozal, L., Neubauer, D. N., O'Donnell, A. E., Ohayon, M., Peever, J., Rawding, R., Sachdeva, R. C., Setters, B., Vitiello, M. V., Ware, J. C., & Adams Hillard, P. J. (2015). National Sleep Foundation's sleep time duration recommendations: methodology and results summary. 

(1), 40–43. https://doi.org/10.1016/j.sleh.2014.12.010

American Psychological Association. (2017, July). 

https://www.apa.org/ptsd-guideline/patients-and-families/cognitive-behavioral

Learn about how you can improve your sleep by having a consistent sleep schedule.